The present invention relates to a film cassette, particularly an X-ray film cassette. More particularly, the invention relates to a mechanism in a film cassette for locking and releasing a cassette cover to and from its base.
In flat film cassettes the cover is usually connected to the base using a hinge on one edge. When this technique is used, the lock and release mechanism is situated on the side of the cassette opposite to the hinge. There are, however, cassettes in which the cover is placed essentially in a parallel attitude onto the base and there secured by lock elements situated on at least two opposite sides of the cassette. In the case of larger cassettes of the first mentioned type, it is usual to provide several lock elements along the locking side.
Now, in the case of cassettes such as have been discussed, it has become evident that there is a danger that a cassette can rather easily spring open if the cassette experiences a jolt in a certain direction. The probability that a cassette will some time fall to the floor in an X-ray laboratory (where several cassettes are always being dealt with at the same time) is relatively high. The opening of a cassette is especially unpleasant when it contains a film that has already been exposed. Naturally, the film becomes unusable, and the patient must be asked to undergo another X-ray procedure and must be subjected to the radiation dosage a second time.